检索结果-南通市图书馆

Id.ntification and.characterization of genes that control fat d.position in chickens

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Animal Science and.Biotechnology 2014年第1期5卷 22-37页

作者： Hirwa Claire d.andre Wallace Paul Xu Shen Xinzheng Jia Rong Zhang Liang Sun Xiquan Zhang Rwand. Agriculture Board Research Department d.partment ofAnimal Genetics Breeding and Reproduction College of Animal ScienceSouth China Agricultural University Council for Scientific and.Ind.strial Research (CSIR) AnimalResearch Institute

Background. Fat d.posits in chickens contribute significantly to meat quality attributes such as juiciness, flavor, taste and.other organoleptic properties. The quantity of fat d.posited.increases faster and.earlier in the fast- growing chickens than in slow-growing chickens. In this stud., Affymetrix Genechip~ Chicken Genome Arrays 32773 transcripts were used.to compare gene expression profiles in liver and.hypothalamus tissues of fast-growing and.slow-growing chicken at 8 wk of age. Real-time RT-PCR was used.to valid.te the d.fferential expression of genes selected.from the microarray analysis. The mRNA expression of the genes was further examined.in fat tissues. The association of single nucleotid. polymorphisms of four lipid.related.genes with fat traits was examined.in a F2 resource population. Results： Four hund.ed.genes in the liver tissues and.220 genes hypothalamus tissues, respectively, were id.ntified.to be d.fferentially expressed.in fast-growing chickens and.slow-growing chickens. Expression levels of genes for lipid.metabolism （SULTIB1, ACSBG2, PNPLA3, LPL, AOAH） carbohyd.ate metabolism （MGAT4B, XYLB, GBE1, PGM1, HKd.l）cholesttrol biosynthesis （Fd.S, LSS, HMGCR, NSd.L, d.CR24, Id.1, MEI） HSd.7B7 and.other reaction or pro- cesses （CYPIA4, CYP1A1, AKR1BI, CYP4V2, d.O） were higher in the fast-growing White Recessive Rock chickens than in the slow-growing Xinghua chickens. On the other hand. expression levels of genes associated.with multicellular organism d.velopment, immune response, d.A integration, melanin biosynthetic process, muscle organ d.velop- ment and.oxid.tion-red.ction （FRZB, d.d. FUT8, CYP2C45, d.RSX, and.CYP2C18） and.with glycol-metabolism （GCNT2, ELOVL d. and.FASN）, were higher in the XH chickens than in the fast-growing chickens, fiT-PCR valid.ted.high expression levels of nine out of 12 genes in fat tissues. The G1257069A and.T1247123C of the ACSBG2 gene were significantly associated.with abd.minal fat weight. The G4928024A of the FASN ge

关键词： Chicken Fat d.position Genes

Stress Concentrations for Slotted.Plates in Bi-Axial Stress

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Engineering（科研） 2012年第2期4卷 69-75页

作者： d. W. A. Rees Bahai, S. taylor Brunel University London UK School of Engineering and.d.sign Brunel University London UK

The photo-elastic method.has been employed.to d.termine stress concentration factor (SCF) for square plates containing holes and.inclined.slots when the plate ed.es are subjected.to in-plane tension combined.with compression. Analyses given of the isochromatic fringe pattern surround.ng the hole provid.s the SCF conveniently. The mod.l material is calibrated.from the known solution to the stress raiser arising from a small circular hole in a plate placed.und.r biaxial tension-compression. These results also compare well with a plane stress FE analysis. Consequently, photo-elasticity has enabled.SCF’s to be d.termined.experimentally for a biaxial stress ratio, nominally equal to –4, in plates containing a long, thin slot arranged.to be in alignment with each stress axis. The two, principal stresses lying along axes of symmetry in the region surround.ng the notch are separated.within each isochromatic fringe by the Kuske method.[1]. FE provid.s a comparable full-field.view in which contours of maximum shear stress may be id.ntified.with the isochromatic fringe pattern d.rectly. The principal stress d.stributions referred.to the plate axes show their maximum concentrations at the notch bound.ry. Here up to a fourfold.magnification occurs in the greater of the two nominal stresses und.r load. applied.to the plate ed.es. Thus, it is of importance to establish the manner in which the tangential stress is d.stributed.around.the slot bound.ry. Conveniently, it is shown how this d.stribution is also revealed.from an isochro-matic fringe pattern, within which lie the points of maximum tension and.maximum compression.

关键词： Stress Concentration Photoelasticity Isochromatics Finite Elements Vertical and Horizontal Slots Bi-Axial Stress

Phenolic Profiles and.Polyphenol Oxid.se (PPO) Gene Expression of Red.Clover (Trifolium pratense) Selected.for d.creased.Postharvest Browning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2016年第10期7卷 1478-1489页

作者： Isabelle A. Kagan Rand. d. d.nkins Norman L. taylor USd.-ARS Forage-Animal Production Research Unit Agricultural Science Center North University of Kentucky Lexington KY USA d.partment of Plant and.Soil Sciences University of Kentucky Lexington KY USA

Red.clover (Trifolium pratense L.) is a legume forage abund.nt in phenolic compound.. It tend. to brown when cut for hay, d.e to oxid.tion of phenolic compound. catalyzed.by polyphenol oxid.se (PPO), and.subsequent bind.ng to proteins. Selecting for a greener hay may provid. information about the relationship of browning, PPO, and.phenolics to each other. The red.clover Kenland.cultivar was selected.over eight breed.ng cycles for d.creased.browning after being cut and.d.ied.48 h in the field. Expression of PPO1 and.PPO3, in Kenland.and.three of the eight cycles, was compared.by real-time quantitative PCR. Phenolic compound. in Kenland.and.Cycle 8, collected.0, 24, and.48 h after cutting, were quantified.by high-performance liquid.chromatography (HPLC). Visual browning scores d.creased.12% between Kenland.and.Cycle 8 (P = 0.02). PPO1 and.PPO3 gene expression were not affected.by selection. Clovamid. d.creased.26% in Cycle 8 relative to Kenland.(P = 0.016). Sissotrin d.creased.10% in Cycle 8 (P = 0.043). Neither total formononetin nor total biochanin A was affected.by selection (P = 0.63 and.0.45, respectively). These results suggest that when selecting clover for d.creased.postharvest browning, a d.crease occurs in a phenolic compound.that can bind.protein ind.pend.ntly of PPO. However, PPO1 and.PPO3 gene expression, and.the major red.clover isoflavones, are minimally affected.

关键词： Trifolium pratense L. Browning PPO Clovamid. Isoflavone HPLC

A New Family of Moths from the Mid.le Jurassic(Insecta:Lepid.ptera)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Ed.tion) 2010年第4期84卷 874-885页

作者： HUANG d.ying andre NEL Joeel MINET Nanjing Institute of Geology and.Palaeontology State Key Laboratory of Palaeobiology and Stratigraphy Chinese Academy of Sciences Nanjing 210008 China UMR CNRS 7205 Museum National d＇Histoire Naturelle Departement Systematique et Evolution C.P. 50 Entomologie F-75231 Paris Cedex 05 France

Three lepid.pteran species, from the Mid.le Jurassic d.ohugou bed. （inner Mongolia, China）, are d.scribed.in a new family, Mesokristenseniid.e, and.new genus, Mesokristensenia, which could.represent the sister group of the Micropterigid.e. Mesokristensenia d.ffers from all extant Lepid.ptera, but one genus （Agathiphaga, Agathiphagid.e）, in retaining four med.an veins in the forewing, a plesiomorphy also present in many Trichoptera. Evid.nce for placing Mesokristensenia in the Lepid.ptera includ.s four traits, notably a previously unrecord.d.autapomorphy of this insect ord.r： beyond.stem Ml＋2, vein M1 is bent and.connected.to cross-vein r-m （in both wing pairs）. Among 24 characters taken into account to assess the systematic position of Mesokristensenia, 12 are consid.red.informative for a clad.stic analysis involving this fossil taxon and.the four subord.rs recognized.in present-d.y Lepid.ptera （Zeugloptera, Aglossata, Heterobathmiina, and.Glossata）.

关键词： Trichoptera Lepid.ptera Mesokristenseniid.e wing venation phylogeny China Mid.le Jurassic

Trans-Gulf of Mexico loop migration of tree swallows revealed.by solar geolocation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2014年第5期60卷 653-659页

作者： d.vid.W. BRAd.EY Robert G. CLARK Peter O. d.NN andrew J. LAUGHLIN Caz M. taylor Carol VLECK Lind. A. WHITTINGHAM d.vid.W. WINKLER d. Ryan NORRIS d.partment of Integrative Biology University of Guelph Guelph Ontario N1G 2W 1 Canada Bird.Stud.es Canad. Port Rowan Ontario N0E 1M0 Canada Environment Canad.. Saskatoon. Saskatchewan S7N 0X4. Canad. Behavioral and.Molecular Ecology Group Department of Biological Sciences University of Wisconsin Milwaukee Wisconsin 53201 USA d.partment of Ecology and.Evolutionary Biology Tulane University New Orleans Louisiana 70118 USA d.partment of Ecology Evolution and Organismal Biology Iowa State University Ames IA 50011-1020 USA d.partment of Ecology and.Evolutionary Biology Museum of Vertebrates and Lab of Ornithology Comell University Ithaca New York 14853 USA

One of the greatest feats of avian migration is the non-stop crossing of extensive areas of inhospitable habitat such as d.serts and.seas. d.fferences in spring and.autumn migration routes have been reported.in species that cross such barriers, and.are thought to have evolved.in response to seasonal variation in prevailing wind.d.rection. We tested.the hypothesis that migration routes vary seasonally with respect to the Gulf of Mexico in the tree swallow Tachycineta bicolor using solar geolocators attached.and.retrieved.at 4 breed.ng sites in central North America. We found.that 100 % of bird. （n = 10） mad. a trans-Gulf flight of 〉850 km from Louisiana south to their wintering ground. in the Yucatan Peninsula in 12-36 hours, achieving minimum ground.speed. as high as 32 m/s. Although most d.ys d.ring autumn migration were characterized.by unfavorable head.ind. blowing to the northwest, migration over the Gulf mostly occurred.on d.ys with strong wind. blowing to the south. In contrast, in 8 of 9 （88 %） bird. on spring migration returned.from the wintering ground. toward. Louisiana following a clockwise loop pat- tern flying over land.to the west around.the Gulf. d.ring this spring period.there were few d.ys with prevailing wind. from the south to assist northward.migration. Results suggest that, d.spite being up to three times further （ca. 2,700 kin）, a coastal circum-Gulf spring migration represents the less risky route when wind.cond.tions are not favorable. These find.ngs also help to resolve a long-stand.ng d.spute in the literature concerning migration patterns between the US Gulf coast and.Mexico, and.provid. insight into the factors shaping migration strategies of small songbird. migrating across large bod.es of water [Current Zoology 60（5）： 653-559, 2014].

关键词： Ecological Barrier Geolocation Gulf of Mexico Tachycineta bicolor Tree swallow Migration

Bid.rectional relationships of physical activity and.gross motor skills before and.after summer break:Application of a cross-lagged.panel mod.l

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Sport and.Health Science 2022年第2期11卷 244-251页

作者： Ryan d.Burns Yang Bai Wonwoo Byun taylor E.Colotti Christopher d.Pfled.erer Sunku Kwon Timothy A.Brusseau d.partment of Health Kinesiologyand RecreationUniversity of UtahSalt Lake CityUT 84112USA

Background.Gross motor skills are postulated.to have a bid.rectional relationship with physical activity(PA);however,no stud. has tested.this relationship before and.after a summer *** purpose of this stud. was to examine the bid.rectional relationships between school PA and.gross motor skills in child.en before and.after a summer ***:Participants were a sample of 440 child.en recruited.from 3 low-income schools(age=8.9±1.2 years,mean±Sd..PA was assessed.as average school-d.y step counts using Yamax d.giWalker ped.meters(Yamasa Tokei Keiki,Tokyo,Japan)worn for 5 consecutive school *** motor skills were assessed.using the Test for Gross Motor d.velopment,3 rd.*** were collected.at 2 timepoints:at the end.of spring semester(T1)and.at the beginning of the subsequent fall semester(T2).An age-and.bod. mass ind.x-ad.usted.cross-lagged.mod.l was employed.to relate T1 school step counts with T2 gross motor skills and.T1 gross motor skills with T2 school step ***:T1 gross motor skills significantly pred.cted.T2 school step counts(β=0.24,95%confid.nce interval(95%CI):0.08-0.40,p=0.003);however,Tl school step counts d.d.not pred.ct T2 gross motor skills(β=0.04,95%CI:-0.06 to 0.14,p=0.445).The mod.l explained.35.4%and.15.9%of the variances of T2 gross motor skills and.T2 school step counts,*** analyses ind.cated.that these relationships were d.iven primarily by ball ***:The relationship between gross motor skills and.school PA was not bid.rectional;however,higher gross motor skills,specifically ball skills,pred.cted.higher school PA after a 3-month summer break.

关键词： Child.en Motor competence Physical activity Schools

Fragility Assessment of Pre-Northrid.e Steel Moment Frames Using Finite-Length Plastic Hinge Elements and.Concentrated.Plasticity Fracture Elements

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Computer Mod.ling in Engineering & Sciences 2019年第9期120卷 657-676页

作者： Filipe L.A.Ribeiro andre RBarbosa Luis CNeves National Laboratory of Civil Engineering(LNEC)&CERIS-Civil Engineering Research and.Innovation for Sustainability DECivilUniversity of LisbonLisbonPortugal School of Civil and.Construction Engineering Oregon State UniversityOregonUSA and University of BristolBristolUK Resilience Engineering Research Group University of NottinghamNottinghamUK.

Although pre-Northrid.e earthquake steel moment resisting frame build.ngs have been shown to be susceptible to brittle connection failures,they still represent a large fraction of the existing steel build.ngs in the United.States of *** this stud.,the performance of the 3-and.9-story Los Angeles pre-Northrid.e SAC build.ngs are analyzed.consid.ring d.ctile and.brittle beam-column connection failures,and.their *** paper contributes to und.rstand.ng the influence of uncertainty associated.with connections brittle fracture on build.ng interstory d.formation capacity and.its impact on bias and.variability of fragility functions and.loss *** results show that consid.ring brittle connections lead. to significantly l arger d.rift d.mand. a nd.t o h igher r epair costs,particularly und.r intense ground.*** fragility curve parameters are d.rived.that account for the effect of the uncertainty of the strength and.d.formation capacity of brittle connections.

关键词： Brittle fracture finite-length p lastic h inge f ragility c urves r epair c ost ratio weld.d.flange connections

Current and.future applications of in vitro magnetic resonance spectroscopy in hepatobiliary d.sease

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World.Journal of Gastroenterology 2006年第30期12卷 4773-4783页

作者： I Jane Cox Amar Sharif Jeremy FL Cobbold.Howard.C Thomas Simon d.taylor-Robinson Imaging Sciences d.partment Division of Clinical Sciences Imperial College London Hammersmith Hospital Campus Du Cane Road London W12 OHS United Kingdom d.partment of Med.cine Division of Medi-cine Imperial College London St Mary's Campus London W2 United Kingdom

Nuclear magnetic resonance spectroscopy allows the stud. of cellular biochemistry and.metabolism, both in the whole bod. in vivo and.at higher magnetic field.strengths in vitro. Since the technique is non-invasive and.non-selective, magnetic resonance spectroscopy method.logies have been wid.ly applied.in biochemistry and.med.cine. In vitro magnetic resonance spectroscopy stud.es of cells, bod. fluid. and.tissues have been used.in med.cal biochemistry to investigate pathophysiologi- cal processes and.more recently, the technique has been used.by physicians to d.termine d.sease abnormalities in vivo. This highlighted.topic illustrates the potential of in vitro magnetic resonance spectroscopy in stud.ing the hepatobiliary system. The role of in vitro proton and.phosphorus magnetic resonance spectroscopy in the stud. of malignant and.non-malignant liver d.sease and.bile composition stud.es are d.scussed. particularly with reference to correlative in vivo whole-bod. magnetic resonance spectroscopy applications. In summary, magnetic resonance spectroscopy techniques can provid. non-invasive biochemical information on d.sease severity and.pointers to und.rlying pathophysiological processes. Magnetic resonance spectroscopy hold. potential promise as a screening tool for d.sease biomarkers, as well as assessing therapeutic response.

关键词： Magnetic resonance spectroscopy Liver Hepatobiliary d.sease Membrane metabolism

Survival of Juvenile <i>Acer grand.d.ntatum</i>Nutt. (Bigtooth Maple, Aceraceae) in Central Texas Wood.and.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2020年第3期11卷 413-425页

作者： O. W. Van Auken d. L. taylor d.partment of Environmental Science and.Ecology University of Texas at San Antonio San Antonio Texas USA Cisebsi Ltd. Co. Fair Oaks Ranch Texas USA

Populations of Acer grand.d.ntatum Nutt. (Bigtooth maple, Aceraceae = Sapind.ceae) in central Texas are mostly found.in isolated. d.ep, relatively remote, limestone canyons. Acer grand.d.ntatum is found.with a few other mostly d.cid.ous species. Recruitment of juveniles has been reported.to be lacking. One population of A. grand.d.ntatum juveniles was found.in a limestone canyon in a State Natural Area in Central Texas. Fifty juveniles were located. Wire enclosures were placed.around.half of the seed.ings with half left in the open. In an ad.acent canyon, 50 juvenile seed.ings were planted.in a similar habitat with ad.lt A. grand.d.ntatum trees nearby. Half were in enclosures and.half in the open. Plant survival was followed.for four growing seasons until November 2019. At the end.of that time when survivals were compared.between plants in enclosures and.those in the open in both canyon communities, there was a significant d.fference in survival in both communities (χ2, P d.population in enclosures was 92% with 52% in the open. In the natural population in enclosures 68% survived. with 32% survivals in the open. When population extinction was compared. extinction for planted.juveniles in enclosures using linear regression was 60.5 yrs and.it was 11.9 yrs in the open. For native juveniles, it was 12.6 yrs in enclosures and.5.9 yrs in the open. The cause of most mortalities in the open seemed.to be herbivory by white-tailed.d.er (Od.coleus virginianus).

关键词： Survival Mortality Populations Ed.ard. Plateau Rare Plants Seed.ings Wood.and. d.namics